Chapter 12: Shellcoding – Evading Antivirus

Ever since the Creeper worm made its rounds among PDP-10 mainframe computers on the ARPANET in 1971, the sophistication of malware has increased radically. Without knowledge of what the future had in store, few people fully understood the potential of this newborn beast. One of the pioneers who did understand the potential of malware is Fred Cohen, the computer scientist who first defined what a computer virus is and also invented the first methodology for combating computer viruses. In his seminal 1987 paper Computer Viruses – Theory and Experiments, Cohen showed that the absolute and precise detection of computer viruses is an undecidable problem – that is, a problem that requires a yes or no judgment, but no system can possibly always give the right answer (or any answer at all). He showed the simple relationship between intersystem sharing ability and the potential for viral spread. In the years since, the sharing...